1．There is ________ useful book on the desk，and _________ useful book belongs to my brother．
A．a；the B．an；the C．a；an
2．I remember he came back ________ a cold morning．
A．in B．for C．on
3．An old friend of my sister’s always helps my brother and _________ with _________ lessons．
A．I；our B．me；our C．me；ourselves
4．Simon heard his neighbour __________ for help at night．
A．calls B．called C．calling
5．It’s cold here．Please keep the window __________．
A．close B．closed C．closing